Large companies keep government secrets every day. What do the employees have to gain? It's called not going to prison. There are ~4M cleared individuals in the US right now. They keep secrets every day. It would not be hard to put a team into place of cleared workers and literally seal them away in contained rooms and tell everyone else to go away. They're called SCIFs. You go in and leave your cell phones outside with any other electronics and do your top secret work. On the outside they appear as normal offices. My point is, this industry already knows how to work without you knowing anything. You're basing your hunches on faith and naivety about how intelligence agencies work.
I think frankly it is you who doesn't understand how intelligence agencies work. Massive conspiracies have leaks. No agency would set up something as broad and involving as many people as you describe and expect it to stay secret.
Also problematic is your theory about motivation. That Mark Zuckerberg and his chief legal officer are compelled to take bet-the-company risks and lie to their shareholders under threat of prison. There is no such law. They are only restricted in how much they can reveal about the requests for info.
1. It wouldn't have to be a massive conspiracy. It would just require access to the data through a few people. It's called compartmentalizing and it's how they work.
2. There certainly are laws that govern classified information and the gathering of it. Leaking US government secrets is against the law, period. Are you arguing that's not the case? Verizon was required to assist the government by law. What makes FB and Google+ exempt from the same rules?
You can dig further and find out I'm not just making stuff up. This really is how they work, frankly.
